Oscillating ice breaker

ABSTRACT

An elongated tongue-like ice breaker mounted on the bow of a vessel and pivoted to swing with a short oscillating stroke in a vertical plane, to drive under and lift a layer of ice. The tongue is powered by an oscillator having its effective power stroke aligned with the plane of tongue motion and at a substantial lever arm for maximum efficiency. Deflection of the tongue and the oscillation of the entire tongue divert broken pieces of ice upward and outward, clear of the vessel, a minimum of propulsive power being needed even with thick ice. To minimize loads on the oscillator and the vessel, the tongue is primarily of buoyant construction.

United States Patent Stoffelet al.

[is] 3,658,024 [4 1 Apr. 25, 1972 221 Filed:

211 Appl.No.: 861,952

1541 OSCILLATING ICE BREAKER [72] inventors: Olly 0. Stoifel, San Diego, Calif. l73| Assignee: Stoii'el Engineering Corporation, San Diego Calif Sept. 29, 1969 52 U.S. c1. ..114/4o [5 I] Int. Cl. ..B63b 35/10 [5 8] Field of Search ..l 14/40-42 [56] References Cited UNITED STATES PATENTS 3,572,273 3/1971 Wood ..1 14/40 3,530,314 9/1970 Rastorguev et a1. 14/40 3,545,395 12/1970 Rastorguev et al. ..1 14/41 3,045,628 7/1962 Waasetal. ........ll4/40 Primary Examiner-Trygve M. Blix Attorney-Carl R. Brown s7 ABSTRACT An elongated tongue-like ice breaker mounted on the bow of a vessel and pivoted to swing with a short oscillating stroke in a vertical plane, to drive under and lift a layer of ice. The tongue is powered by an oscillator having its eflective power stroke aligned with the plane of tongue motion and at a substantial lever arm for maximum efficiency. Deflection of the tongue and the oscillation of the entire tongue divert broken pieces of ice upward and outward, clear of the vessel, a minimum of propulsive power being needed even with thick ice. To minimize loads on the oscillator and the vessel, the tongue is primarily of buoyant construction.

11 Claims, 8 Drawing Figures PATENTED APR 2 5 I972 SHEET 1 BF 3 Fig- 3 INVENTOR. 25 QULUM gUWIHI baa Ol-LY 0, TOFFEL l4 25 BY a ATTORNEY PATENTEDAPR 25 :972

SHEET 2 BF 3 INVENTOR. OLLY o. STOFFEL Kan/K 6mm.

ATTQRN EY PATENTEDAPR 25 m2 3, 658,024

swam 3 UF 3 54 lnlfll 54 INVENTOR. OLLY O. STOFFEL ATTORNEY OSCILLATING ICE BREAKER BACKGROUND OF THE INVENTION Conventional techniques of ice breaking usually involve the use of a rugged vessel driven into the ice with considerable power, or driven up on the ice and using the weight of the vessel to break the ice. The vessel must then be driven through the broken ice to clear a channel. The continuous pounding and the pitching motion of the entire vessel imposes considerable strain on the structure and the crew.

SUMMARY OF THE INVENTION The ice breaker described herein comprises an elongated tongue-like member mounted on he bow of a vessel and pivoted to swing in a vertical plane with a short oscillatory stroke. Power is provided by an oscillator mounted on the tongue and having its effective power stroke aligned with the plane of tongue motion, the oscillator being on an extended arm for maximum leverage. The tongue is driven at a high frequency of oscillation to lift and break up the ice, the broken ice being deflected upward and outward over the tongue, and clear of the vessel, resulting in a minimum requirement of propulsive power for the vessel. The oscillator power source is mounted in the vessel and coupled to the oscillator through a simple motion compensating drive means and very little oscillation is transferred to the vessel. To minimize loads the major portion of the tongue is a buoyant structure, and is adaptable to fit various vessel configurations.

Other objects of this invention will become more apparent upon a reading of the following detailed description and an examination of the drawings wherein like reference numerals designate like parts throughout and in which:

FIG. 1 is a side elevation view of the ice breaker mounted on a vessel.

FIG. 2 is a top plan view with the oscillator drive means omitted for clarity.

FIG. 3 is a front elevation view of the assembly.

FIG. 4 is an enlarged sectional view taken on line 4-4 of FIG. 2.

FIG. 5 is an enlarged sectional view taken on line 5-5 of FIG. 4.

FIG. 6 is a sectional view taken on line 6-6 ofFIG. 5.

FIG. 7 is a sectional view taken on line 7-7 ofFIG. 4.

FIG. 8 is a side elevation view showing the operation of the ice breaker.

DESCRIPTION OF THE PREFERRED EMBODIMENT The ice breaker is shown mounted on the bow of a marine vessel 10, the configuration of which can vary since the structure is adaptable to existing vessels of suitable type.

Projecting forward from the vessel on the longitudinal center line is a rigid support arm 12, on which the tongue 14 is pivotally mounted on a bearing 16, to swing in a vertical plane. Extending upwardly from the rear of support arm 12 is a post 18, secured to the vessel in a suitable manner. In a vessel built especially for the purpose, the support arm and post would effectively be extensions of the keel, or the primary hull structure, the particular configuration being adapted to the vessel for maximum strength.

The tongue 14 is an elongated member converging in width and depth toward the forward end, which terminates in an upwardly and rearwardly inclined ramp face 20. The tongue has a flattened ovoid cross section and is constructed as a closed steel shell with internal bracing as necessary, depending on the size of the structure. At the rear the tongue is shaped to fit closely around the bow of the vessel and extends on both sides of the bow, with a large cavity 22 in the underside to provide access to hearing 16, as in FIG. 4. For bouyancy the shell structure of the tongue 14 is filled with flotation type plastic foam 24. As much of the tongue structure as possible, including the side portions 25 extending around the bow, is a foam filled shell, in order to reduce loads on the bearing and the vessel. The type olfoam normally used for buoyancy purposes will not become waterlogged, so the tongue will retain its buoyancy even if damaged. On the upper rear portion of the tongue are deflector wings 26 curing upwardly and outwardly on both sides of the bow, preferably extending slightly above the top of the hull to deflect broken ice clear of the interior of the vessel. The deflector wings 26 blend smoothly into the tongue and the overall contours of the structure are as smooth as possible to avoid jamming of broken ice. At the forward end of tongue 14 on opposite sides of ramp face 20, are outwardly projecting, upwardly arched deflector plates 28. On the top portion 30 of the tongue, at the center and immediately behind ramp face 20, is a vertical splitter blade 32.

Tongue 14 has a pair of bearing plates 34 extending into cavity 22 in spaced parallel relation to straddle support arm 12. The bearing 16 comprises a cylindrical hub 36 through the bearing plates and support arm, held by end plates 38 which are secured by bolts 40, the hub acting as a spacer to ensure a free pivotal action, as in FIGS. 4 and 7. For stability the bearing plates 34 are connected rearwardly of the hearing by tie bolts 42, which pass through arcuate slots 44 in the support arm 12, the slots having their center of radius at the axis of hub 36. A suitable bearing of this type, used in a similar manner, is shown in considerably more detail in my copending U.S. Pat. application, Ser. No. 660,389, filed Aug. 14, 1967 and entitled Vibrating Ripper".

Fixed to tongue 14 and extending upwardly above bearing 16 is a mounting post 46, on top of which is a suitably braced platform 48. Secured to the platform is an oscillator 50 of the rotary eccentric type, having a drive shaft 52 with pulleys 54 on opposite ends. The oscillator 50 is fully disclosed in my copending U.S. Pat. application, filed Sept. 19, 1969 and entitled Oscillating Power Unit. While other vibrating or oscillating means could be used, this particular oscillator is ideally suited to the purpose since the oscillating power is essentially limited to a linear motion and can be: aligned to apply the power in the optimum direction. In the present arrangement the oscillation is generally horizontal in a fore and aft direction, causing the forward end of the tongue 14 to rise and fall.

To stablize the oscillating mechanism, mounting post 46 is slidably held between spaced parallel guide arms 56, extending forwardly from post 18. On the forward end of guide arms 56 is a front spring adjuster 58, from which a front spring 60 extends to mounting post 46 below the platform 48. At the rear of the guide arms is a rear spring adjuster 62, from which a rear spring 64 extends to the mounting post 46, which is thus balanced between the two springs. The spring adjusters may be operated by screw means, or by conventional hydraulic means to adjust the compression load of the individual springs. This provides for damping and control of the oscillating motion and also permits vertical adjustment. of the forward end of the tongue 14 in relation to the water line of the vessel, to ensure proper engagement with the ice.

Power for the oscillator 50 is provided by a motor 66 mounted on internal structure 68 of the vessel. Installing the motor in the vessel rather than on the tongue reduces the weight of the moving structure. To apply driving power while the oscillator is moving, an arrangement of tensioned belts has been found satisfactory, although other means could be used. In the arrangement shown, a cantilever arm 70 is pivotally attached to the top of an upward extension 72 of post 18, the

arm extending forward and swinging vertically. The arm 70 iscomposed of a pair of spaced parallel side plates 74 straddling post extension 72 and being pivotal on a bearing sleeve 76 passing through the extension and both side plates, as in FIG. 5. Rotatably mounted in bearing sleeve 76 is a shaft 78 having pulleys 80 fixed thereon on opposite sides of the arm 70. One end of shaft 78 carries a driven pulley 82, which is coupled by a drive belt 84 to the drive pulley 86 of motor 66. At the forward end, side plates 74 have corresponding longitudinal slots 88, and between the side plates is a trunnion block 90 having fattened ends 92 which ride in the slots. Rotatably mounted in trunnion block 90 is a transfer shaft 94 on which are inner pulleys 96, coupled by belts 98 to the pulleys 80. On the outer ends of transfer shaft 94 are outer pulleys 100, coupled by belts 102 to the pulleys 54 on oscillator 50.

To maintain tension in belts 102, the arm 70 is urged upwardly by a lift spring 104 between a retainer 106 on the underside of the arm forward of the pivot and a step 108 on post 18. The lower end of spring 104 is held on a threaded pin 110 threaded into post 18 and secured by a lock nut 112, which allows adjustment of the spring load.

Attached to trunnion block 90 and extending between side plates 74 is a pressure plate 114 having a threaded stud 116 on which is an adjustable stop 118, the stop being slidably held between the side plates. Extending from bearing sleeve 76 is a stop plate 120 having a fixed stop 122, a spring 124 inserted between stops 122 and 118 maintaining tension on belts 98. Side plates 74 are held in alignment by upper and lower clamp plates 126 secured by bolts 128.

in operation, the oscillator 50 has a fore and aft power stroke which, amplified through the lever arm of mounting post 46 about bearing 16, causes the forward end of the tongue 14 to pulsate vertically. The angular motion of the tongue is not great, being on the order of to However, the oscillation rate is high, on the order of 2,400 cycles per minute in a working model which was successfully tested. The tongue 14 is set so that the ramp face 20 slides under and tends to lift the ice as the vessel is propelled forward. With the oscillation in operation the pulsating tongue sets up powerful vibration waves through the ice and cracks pieces of ice upwardly, as indicated at 134 in FIG. 8. Instead of being driven down, as in the usual ice breaking operation, the broken ice is lifted and thrown to the sides, initially by deflector plates 28 and then by deflector wings 26, to clear a passage for the vessel. Pieces of ice which move up over ramp face 20 are broken by splitter blade 32 and any pieces which may continue to travel along the top of the tongue are deflected from the moving mechanism by a further blade 136 on the top of the tongue, cooperating with a cutter blade 138 projecting forwardly and downwardly from the forward end of guide arms 56. At the rear of the tongue all of the broken ice is deflected outwardly clear of the vessel by wings 26.

It should be noted that it is the oscillation which makes the ice breaker so effective. The constant high frequency vibration as the edge of the ice is lifted, literally shakes the ice apart for a considerable distance on either side of the tongue, making it easy to clear a channel with minimum propulsive power and with very little lurehing or shaking of the vessel. There is no tendency for the ice to jam on the tongue, since the con stant oscillation keeps the ice in motion and tends to walk" the broken pieces along the tongue.

For further avoidance of jamming, it is desirable to minimize the working clearance between deflector wings 26 and the hull of the vessel. To prevent undue wear on the vessel, hardened wear plates 140 are attached to the vessel in the appropriate areas, as in FIG. 2, and may be made replaceable. In the event that the tongue is subjected to a side load, as by ramming an obstruction, the wear plates provide bearings to support and stabilize the tongue and prevent distortion of bearing 16.

Since the ice is broken primarily by vibration rather than by impact, the tongue structure need not be particularly massive. This makes it practical to use the foam filled shell shown, which reduces structural leads and requires a minimum of operating power. Further, the buoyancy reduces the longitudinal unbalance of the vessel due to the added load at the bow.

Having described my invention, I now claim.

1. in an oscillating ice breaker for mounting on the forward end ofa marine vessel,

an elongated tongue having a forward ice engaging upper face surface extending forwardly from the vessel with said tongue being pivotally mounted on the vessel to move said face in a substantially vertical plane, oscillator means coupled to said tongue for exerting a power stroke to said tongue in the direction of swing of the tonan said upper face surface being angled downwardly in the forward direction to pass under the ice in normal movement of the vessel, whereby said swing movement of said face causes the ice to break up over and about the upper face surface.

2. An oscillating ice'breaker according to claim 1 including,

damping means connected to said oscillator to limit the angular motion of said tongue.

3. An oscillating ice breaker according to claim 1 wherein,

said oscillator means is mounted above and substantially vertical to said pivotal mounted connection.

a. An oscillating ice breaker according to claim 1 wherein,

said oscillator means creates a substantially horizontal vibrating force,

and means for converting said oscillator vibrating force to said power stroke of said tongue.

5. An ice breaker according to claim 1 wherein,

the rate of oscillation is on the order of 2,400 cycles per minute.

6. An ice breaker according to claim 1 wherein,

the major portion of said tongue is buoyant.

7. An ice breaker according to claim 1 including,

a fixed support arm projecting forwardly from the vessel and having a bearing on which said tongue is supported, said tongue extending rearwardly of said bearing and fitting closely around the forward end of the vessel.

8. An ice breaker according to claim 7 wherein,

the rear portion of said tongue has upwardly and outwardly curving deflector wings extending on opposite sides of the front end of the vessel.

9. An ice breaker according to claim 8 wherein,

said tongue has outwardly projecting deflector plates on opposite sides of said ice engaging face.

10. An ice breaker according to claim 9 including,

at least one substantially vertical ice splitter blade on the upper portion of said tongue.

11. An ice breaker according to claim 8 wherein,

said tongue has an upwardly extending mounting post above said bearing, said oscillator being secured on top of said mounting post.

12. An ice breaker according to claim 11 including,

a source of power mounted in the vessel,

and motion compensating drive means coupling said source of power to said oscillator.

13. An ice breaker according to claim 11 including,

fixed guide arms extending forwardly from the vessel,

between which said mounting post is slidably retained.

14. An ice'breaker according to claim 13 wherein,

said damping means comprises front and rear springs mounted on said guide arms and engaging said mounting post therebetween.

15. An ice breaker according to claim 14 wherein,

at least one of said springs is adjustable.

16. An ice breaker according to claim 1 wherein,

said tongue is convergent horizontally and vertically forward of the pivotal mounting, and has portions rearward of the pivotal mounting extending outwardly on opposite sides of the vessel in close fitting relation thereto.

17. An ice breaker according to claim 16 wherein,

said tongue has deflector means thereon for guiding broken ice upwardly and outwardly over the tongue. 

1. In an oscillating ice breaker for mounting on the forward end of a marine vessel, an elongated tongue having a forward ice engaging upper face surface extending forwardly from the vessel with said tongue being pivotally mounted on the vessel to move said face in a substantially vertical plane, oscillator means coupled to said tongue for exerting a power stroke to said tongue in the direction of swing of the tongue, and said upper face surface being angled downwardly in the forward direction to pass under the ice in normal movement of the vessel, whereby said swing movement of said face causes the ice to break up over and about the upper face surface.
 2. An oscillating ice breaker according to claim 1 including, damping means connected to said oscillator to limit the angular motion of said tongue.
 3. An oscillating ice breaker according to claim 1 wherein, said oscillator means is mounted above and substantially vertical to said pivotal mounted connection.
 4. An oscillating ice breaker according to claim 1 wherein, said oscillator means creates a substantially horizontal vibrating force, and means for converting said oscillator vibrating force to said power stroke of said tongue.
 5. An ice breaker according to claim 1 wherein, the rate of oscillation is on the order of 2,400 cycles per minute.
 6. An ice breaker according to claim 1 wherein, the major portion of said tongue is buoyant.
 7. An ice breaker according to claim 1 including, a fixed support arm projecting forwardly from the vessel and having a bearing on which said tongue is supported, said tongue extending rearwardly of said bearing and fitting closely around the forward end of the vessel.
 8. An ice breaker according to claim 7 wherein, the rear portion of said tongue has upwardly and outwardly curving deflector wings extending on opposite sides of the front end of the vessel.
 9. An ice breaker according to claim 8 wherein, said tongue has outwardly projecting deflector plates on opposite sides of said ice engaging face.
 10. An ice breaker according to claim 9 including, at least one substantially vertical ice splitter blade on the upper portion of said tongue.
 11. An ice breaker according to claim 8 wherein, said tongue has an upwardly extending mounting post above said bearing, said oscillator being secured on top of said mounting post.
 12. An ice breaker according to claim 11 including, a source of power mounted in the vessel, and motion compensating drive means coupling said source of power to said oscillator.
 13. An ice breaker according to claim 11 including, fixed guide arms extending forwardly from the vessel, between which said mounting post is Slidably retained.
 14. An ice breaker according to claim 13 wherein, said damping means comprises front and rear springs mounted on said guide arms and engaging said mounting post therebetween.
 15. An ice breaker according to claim 14 wherein, at least one of said springs is adjustable.
 16. An ice breaker according to claim 1 wherein, said tongue is convergent horizontally and vertically forward of the pivotal mounting, and has portions rearward of the pivotal mounting extending outwardly on opposite sides of the vessel in close fitting relation thereto.
 17. An ice breaker according to claim 16 wherein, said tongue has deflector means thereon for guiding broken ice upwardly and outwardly over the tongue. 